<p><b>Abstract</b>—We present empirical evidence that metrics on communication artifacts generated by groupware tools can be used to gain significant insight into the development process that produced them. We describe a test-bed for developing and testing communication metrics, a senior level software engineering project course at Carnegie Mellon University, in which we conducted several studies and experiments from 1991-1996 with more than 400 participants. Such a test-bed is an ideal environment for empirical software engineering, providing sufficient realism while allowing for controlled observation of important project parameters. We describe three proof-of-concept experiments to illustrate the value of communication metrics in software development projects. Finally, we propose a statistical framework based on structural equations for validating these communication metrics.</p>